691564868064 has 576 divisors, whose sum is σ = 2454951240000. Its totient is φ = 188603154432.

The previous prime is 691564868017. The next prime is 691564868081. The reversal of 691564868064 is 460868465196.

691564868064 is a `hidden beast` number, since 6 + 9 + 1 + 564 + 8 + 6 + 8 + 0 + 64 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 691564867992 and 691564868010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 109266052 + ... + 109272380.

It is an arithmetic number, because the mean of its divisors is an integer number (4262068125).

Almost surely, 2^691564868064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691564868064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1227475620000).

691564868064 is an abundant number, since it is smaller than the sum of its proper divisors (1763386371936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

691564868064 is a wasteful number, since it uses less digits than its factorization.

691564868064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6480 (or 6459 counting only the distinct ones).

The product of its (nonzero) digits is 59719680, while the sum is 63.

The spelling of 691564868064 in words is "six hundred ninety-one billion, five hundred sixty-four million, eight hundred sixty-eight thousand, sixty-four".